Means for alignment of cover to gear case



Dec. 22, 1942. T. R. SMITH 2,306,233

MEANS FOR ALIGNMENT OF COVER TO GEAR CASE Filed April 23, 1940 PatentedDec. 22, 1942 MEANS FOR ALIGNMENT OF COVER TO GEAR CASE Thomas R. Smith,

Newton, Iowa, assignor to The Maytag Company, Newton, Iowa, acorporation of Delaware Application April 23, 1940, Serial No. 331,167

3 Claims.

The present invention relates to a novel means of aligning a gear casecover with respect to its gear case where an accurate alignment of theseparts is required or desired. In the novel embodiment, this includes thedoweling or pinning into position of the gear case and gear case coverwhere the gear case is made of any relatively hard material suitable forthe purpose such as cast iron, steel, and the like and the cover .ismade of any relatively softer material such as zinc die casting,aluminum die casting and the like. Both the cover and gear case may becompletely and accurately machined before assembly.

In the preferred embodiment, the gear case cover is formed orconstructed with suitably spaced locating projections or lugs adapted tofit into locating holes in the flange or periphery of the gear case.These locating lugs are preferably tapered with their ends of a diameteror cross section somewhat less than the locating holes in the gear casebut with their diameter or cross section greater at their base or wherethey are Joined to the cover than these locating holes so that as thegear case cover and gear case are pressed together they provide anaccurate fit.

In order to hold the necessary holes or openings in the gear case andcover in alignment during the pressing operation, the novel inventioncomprehends the use of an accurate pilot arbor or shaft. After the gearcase cover and gear case are thus pressed together and aligned, thepilot arbor or shaft is removed and the gear case and cover areseparated for the purpose of insertion, positioning and assembly of theworking parts in the gear case.

Further objects are to provide a construction of maximum simplicitefiiciency, economy and ease of assembly and operation, and such furtherobjects, advantages and capabilities as will later more fully appear andare inherently possessed thereby.

The invention further resides in the construc- 1 tion, combination andarrangement of parts illustrated in the accompanying drawing, and whileI have shown therein a preferred embodiment, it is to be understood thatthe same is susceptible of modification and change, and comprehendsother details, arrangements of parts, features and constructions withoutd'eparting from the spirit of the invention.

In the drawing:

Fig. 1 is a view, part in vertical cross section and part in sideelevation, of a disassembled gear case and cover upon an arbor and readyto be pressed together and aligned in accordance with the novelinvention.

Fig. 2 is a similar view but of the parts after they have been pressedtogether.

Fig. 3 is a fragmentary enlarged view in vertical cross section of oneof the locating projections or lugs.

Fig. 4 is a fragmentary plan view of the upper side of the cover.

Fig. 5 is a fragmentary view in vertical cross section through theflange of the cover and gear case with these parts pressed together andshowing the manner of automatically machining the tapered locating lugsor projections to accurately fit the locating holes.

Referring more particularly to the disclosure in the drawing, the novelinvention is shown as embodied in a gear case I and gear case cover 2,which in the illustrated emobdiment are adapted for use in housing thepower unit or driving mechanism of a washing machine, although it is tobe understood that the invention is not limited thereto but may bepracticed in the alignment of any type of gear case and cover whereverit is required or desired that there be an accurate alignment betweenthese parts. For a clearer illustration of the invention, the operatingmechanism or gearin are not disclosed, it being understood, however,that it may consist of any type of drive unit suitable for the purpose.An upstanding sleeve or collar 3, which may form a part of the coverplate 2 and in which is pressed a bushing or bearing 4, provides ajournal in which the operating shaft is adapted to rotate or oscillate.The cover 2 is shown as provided with spaced locating projections orlugs 5 of tapered form with their ends of such diameter or cross sectionas to be readily received and guided into openings 6 provided in aflange or periphery I of the gear case, whereby some slight originalmisalignment can be tolerated. To properly locate these parts, a pilotarbor 8 is provided and adapted to be journalled in the bushing orhearing 4 and at its lower end in a journal or hearing 9 in the gearcase.

As the gear case cover is pressed into the gear case, using the pilotarbor to hold the necessary holes in the gear case and cover inalignment, the locating projections or lugs 5 will be pressed into thelocating holes 6 in the gear case until these tapered members come incontact with the edges or periphery of these locating holes. At thispoint, the pressing together operation automatically machines thetapered lugs or pro]ections to a very accurate fit so that after thegear case and cover are completely pressed together, these parts areaccurately aligned and form a tight and accurate fit with the lugs ad-Jacent their base being automatically shaved or machined to the properposition and the pilot arbor or shaft maintaining the openings in thecover and gear case in the necessary alignment. In order to take care ofshavings from these lugs as they are turned or curled back, the lowersurface of the gear case cover is recessed or undercut at It. This isclearly shown in Figs. 4 and 5 of the drawing, the latter showing theshavings being curled back into this recess from which they are laterremoved before final assembly.

In the preferred embodiment, these locating lugs or projections areunsymmetrically spaced whereby the cover can be assembled in but oneposition and that in the exact relation in which it was originallyaligned with the gear case. Also, in the case of a washing machinedrive, I have found that instead of using a pilot shaft, the agitatorshaft may form its own pilot and thereby eliminate removal of the pilotand complete reassembly of the casing.

Having thus disclosed the invention, I claim:

1. Means for accurately aligning a gear case and gear case cover wherethe cover is of a material softer than that of the gear case and afteralignment, removed for the assembly of the desired gears, comprisingunsymmetrically spaced locating holes in the gear case and tapered lugsdepending from the cover and spaced similarly to the locating holes inthe gear case, the ends of said lugs being of less cross section thanthe holes but their base being of greater cross section so that when thecover and gear case are tightly pressed together to the position theyoccupy when assembled, such pressure machines the surface of said lugsto form an. accurate fit in the locating holes and an accurate alignmentbetween the cover and gear case.

2. Means for accurately aligning a gear case and gear case cover wherethe cover is of a material softer than that of the gear case and afteralignment, removed for the assembly of the desired gears, comprisingspaced locating holes arranged unsymmetrically about the periphery ofthe gear case and tapered depending lugs projecting from the cover andspaced similarly to the locating holes in the gear case, the ends ofsaid lugs being of less cross section than the holes but their basebeing of greater cross section so that when the cover and gear case aretightly pressed together to the position they occupy when assembled,such pressure machines the surface of said lugs to form an accurate fitin the locating holes and an accurate alignment between the cover andgear case, and a. recess formed in the lowerface of the cover adjacentthe base of each lug for the reception of themetal machined from thelugs.

3. Means for accurately aligning a gear case and gear case cover wherethe cover is of a material softer than that of the gear case and inwhich the gear case and cover are provided with bearing surfaces to bealigned for the reception of a common shaft, comprising means foraligning said bearing surfaces, spaced depending locating lugs providedon the periphery of the cover and similarly spaced holes provided in theperiphery of the gear case, the ends of said lugs being of less crosssection than the holes but their base being of greater cross section sothat when the cover and gear case are tightly pressed together to theposition they occupy when assembled, such pressure machines the surfaceof said lugs to form an accurate fit in the locating holes and anaccurate alignment between the cover and gear case.

THOMAS R. SMITH.

